← Back to Red Hat Enterprise Linux 7 Security Technical Implementation Guide

V-204411

CAT II (Medium)

The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed a minimum of eight of the total number of characters must be changed.

Rule ID

SV-204411r982198_rule

STIG

Red Hat Enterprise Linux 7 Security Technical Implementation Guide

Version

V3R15

CCIs

CCI-000195

Discussion

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Check Content

The "difok" option sets the number of characters in a password that must not be present in the old password.

Check for the value of the "difok" option in "/etc/security/pwquality.conf" with the following command:

# grep difok /etc/security/pwquality.conf 
difok = 8

If the value of "difok" is set to less than "8", this is a finding.

Fix Text

Configure the operating system to require the change of at least eight of the total number of characters when passwords are changed by setting the "difok" option.

Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value):

difok = 8